IOS 将文本占位符居中并左对齐

Question

我正在创建一个 IOS 表单来提交反馈。

我想让占位符文本在文本字段中垂直居中，水平左对齐

我试过了

- (void)drawPlaceholderInRect:(CGRect)rect {
    [RGB(36, 84, 157) setFill];

    UIFont *font = [UIFont SingPostLightItalicFontOfSize:_placeholderFontSize fontKey:kSingPostFontOpenSans];
    NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
    paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
    paragraphStyle.alignment = NSTextAlignmentLeft;
    NSDictionary *attributes = @{ NSFontAttributeName: font,
                                  NSParagraphStyleAttributeName: paragraphStyle,
                                  NSForegroundColorAttributeName: [UIColor blackColor]};
    [[self placeholder] drawInRect:rect withAttributes:attributes];

}

但占位符文本位于顶部垂直位置。怎样才能达到金牌。非常感谢

Answer 1

您可以将占位符的 "y" 位置表示您的 "rect" 值作为文本字段 height/2 。如果您使用文本字段的默认属性作为占位符，则还有一个解决方案水平对齐。

喜欢:

var tt : UITextField
        tt.placeholder = ""

Answer 2

以下代码将解决您的问题。我自己试过了。这只是您的代码的额外一行。

- (void)drawPlaceholderInRect:(CGRect)rect {

       CGFloat fontSize = 18;
       UIFont *font = [UIFont systemFontOfSize:fontSize];
       NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
       paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
       paragraphStyle.alignment = NSTextAlignmentLeft;

       NSDictionary *attributes = @{ NSFontAttributeName: font,
                              NSParagraphStyleAttributeName: paragraphStyle,
       NSForegroundColorAttributeName: [UIColor blackColor]};

       CGRect newRect = CGRectInset(rect, 0, rect.size.height/2 - fontSize/2);
       [[super placeholder] drawInRect:newRect withAttributes:attributes];
}

IOS 将文本占位符居中并左对齐

IOS align text placeholder to be in the center and left alignment

objective-c

placeholder

uitextfield

ios